One of the key people in my life was Dr Leonard C Sanford. He was a wealthy trustee of the American Museum [of Natural History]. He was a medical doctor and he was the personal physician of I don't know how many multimillionaires. He was a sportsman; he was... loved shooting and salmon fishing and trout fishing; he had originally had his own private collection which he eventually gave to the Museum. But the most important thing is he was a friend of so many multimillionaires, he was a splendid tennis player, and a... a fascinating raconteur. Everybody loved him and he eventually had become very much interested in the Museum, in the bird collection, in the growth of these collections. And one fact that contributed was that he was competing with the director of the Museum of Comparative Zoology [MCZ] at Harvard [University], Tom Barber, and the question was which museum would eventually have the better collection, the MCZ or the American Museum. Well, that spurred Sanford to ultimate efforts and in no time at all did he build up a collection that vastly outranked the Tom Barber's collection at the Museum of Comparative Zoology. And of course he relied on me to always tell him where to get another collection and where there was an area when an expedition should be sent, and he was most anxious to have the collections worked out and so he was very pleased with me for producing so many papers. And eventually he took me on as if I was another son of his, and he was absolutely marvellous to me. And it was after I was at the Museum in New York for two or three years - it was diagnosed actually by myself, originally - that I had a tumor in my left kidney and that my kidney had to be taken out, and Dr Sanford just took care of me all along. He didn't do the operating or anything like this, but after the operation he invited me to his home in New Haven for convalescence and then he sent me to his trout fishing club in the Catskills for another couple of weeks of convalescence. And it was really absolutely marvellous how he... he... really I can say how he loved me and looked out after me. Well, in a way, this could have been a problem for me, because as we found out later on, when I moved to Harvard, of course I went to his competing institution, and I couldn't have accepted the job in Harvard if Sanford had still been alive. But – I hate to use the word – fortunately he had died a couple years before in 1950 and I was... I no longer had to have qualms... problems accepting the job in Harvard.

The late German-American biologist Ernst Mayr (1904-2005) was a leading light in the field of evolutionary biology, gaining a PhD at the age of 21. He was also a tropical explorer and ornithologist who undertook an expedition to New Guinea and collected several thousand bird skins. In 1931 he accepted a curatorial position at the American Museum of Natural History. During his time at the museum, aged 37, he published his seminal work 'Systematics and Origin of the Species' which integrated the theories of Darwin and Mendel and is considered one of his greatest works.

Walter J. Bock is Professor of Evolutionary Biology at Columbia University. He received his B.Sc. from Cornell and his M.A. and Ph.D. from Harvard. His research lies in the areas of organismal and evolutionary biology, with a special emphasis on functional and evolutionary morphology of the skeleto-muscular system, specifically the feeding apparatus of birds.